Cutting machine



oct. 24, 1933. B. F. BERRY 1,932,239

CUTTING MACHINE Filed Dec. 50, 1931 MVM/we; F. RRY.

Afro/@Wwf Patented Oct. 24, 1933 1,932,239

UNITED vSTATES PATENT OFFICE 1,932,239 CUTTING MACHINE Benjamin F.Berry, St. Louis, Mo., assignor to Berry Machine Company, St. Louis,Mo., a corporation of Missouri Application December 30, 1931 Serial No.583,817'

1 Claim. (Cl. 164-124) This invention relates to cutting machines, andterial, including more or less adhesive substances.

more particularly to a cutter adapted to form This suggests that oneobjection lies in the fric-v round holes in paper and other material.tion due to adhesion, but the same cutting ele- Prior to the presentinvention, cutters of this ment may fail to give satisfactory results inoily 5 kind, known as round hole cutters, have included material. f

a rotary tube having a circular cutting edge at This uncertainty in theold machines involves one end, and a spiral extractor rotatably mountedclogging of the tubular cutting elements which in the tube to transmitthe cuttings, or chips are equipped with spiral ejectors to remove thefrom the cutting edge to a discharge opening in cuttings, and I haveemployed different forms of the tube. ejectors without accomplishing thedesired result. 65

In designing machines of this kind the object A study of the variationsin the work perhas always been to perform the operations at a formed bythe old cutters that appear exactly very high speed without mutilatingthe work. alike has convinced me that there must be some However, inactual practice, the operation of accidental variation in the shape,dimensions the prior machines has been uncertain. Two-or or surfaceconditions of the cutters, and that the 70 more machines of the samedesign made from unknown cause can not be overcome by more the sametools and intended to be exactly alike, accurate finishing of suchcutters. do not have an equal degree of efficiency. The object of thepresent invention is to posivOne of the old machines may givesatisfactory tively eliminate all of this uncertainty, and to resultswhen operated at a reasonably high speed produce cutters wherein thereis a combination 75 in perforating some kinds of sheet material, and ofconditions that positively insure the desired fail to produce the sameresults with other mahigh degree of efficiency in each and every cutter.terial. Another may require a very low .speed More specifically stated,an object is to prowhen operating upon the most favorable mateduce acutter that will normally operate at the rial, and absolutely fail toperform satisfactory desired high speed without objectionable fric- 30operations in other material. l tion at the tubular cutter. Byeliminating this In my experience with such machines I have friction atboth the inside and outside of the found that the eiciency may begreatly incutter, I eliminate the condition that has herecreased ordecreased by removing the cutting eletofore required high pressure andresulted in ments and substituting others that appear to be breakage ofcutters, mutilation of the work, and 85 exactly like the originalcutters. This has led to the danger of igniting the work. the idea thatthe solution lies in proper'sharpen- In actual practice, I have obtainedthe desired ing of the cutting edges, but an investigation results byusing one of the old type spiral exextending over many years has shownthat an tractors in a tubular cutting element having the expert mechanichaving long experience in this usual cutting edge. However, I taperedthe outer 90 work, while using the same methods of sharpenface of thecutter to prevent undue friction being, will produce cutters havingthese varying tween this outer face and the work, and I grooved degreesof efficiency. the inner face of this tubular cutter so as to These oldcutting elements appear exactly form an abutment which transmits therotary 40 alike, but some will satisfy the user, while others motion ofthe cutter to the waste material in the 95 require a very high degree ofpressure at the spiral extractor. work which causes objectionabledepressions or The new cutters having this combination of mutilation ofthe sheet material at the perforaconditions accurately form the roundholes at tions. In some cases the rotating cutter will not high speeds,without overheating or mutilating pass through the work unless thepressure at the the work, while operating under a relatively low 100cutter is great enough to create'intense friction pressure. which issometimes great enough to twist and Service tests in perforating oilymaterial, adbreak the cutting element. Moreover, such frichesivematerial and inflammable material, intion between the cutter and thework results in cluding celluloid, has shown that these new cuta veryhigh temperature and involves the danger ters not only eliminate theuncertainties involved 105 of igniting the work. In fact it hasbeendeemed in the use of the old cutters, but they enable the unsafe to usesuch cutters in perforating cellumachines to safely and accuratelyperform their loid-and other `highly inflammable material. functions invarious kinds of material that could The old cutters have failed toproperly perform not be satisfactorily drilled by the old cutters.

their expected functions in many kinds of ma- With the foregoing andother objects in view, 110

the invention comprises the novel construction,

combination and arrangement of parts hereinafter more specificallydescribed and illustrated in the accompanying drawing, wherein is shownthe preferred embodiment of the invention. However, it is to beunderstood that the invention comprehends changes, variations andmodifications which come within the scope of the claim hereuntoappended.

Fig. 1 is a vertical section illustrating a round hole cutter embodyingthe features of this invention.

Fig. 2 is an enlarged vertical section showing the tubular cutter andthe spiral extractor therein.

Fig. 3 is an exaggerated diagram showing how the tapered outer face ofthe cutter eliminates the highly objectionable friction between the bodyof the work and the cutter.

Fig. 4 is a transverse section taken through the cutter and extractorshown in Fig. 3.

To illustrate one form of the invention, I have shown a cutter in theform of a. rotary tube 1 having a circular cutting edge 2 at its lowerend and a discharge opening 3 near its upper end. A spiral extractor 4is rotatably mounted in said tube to transmit the cuttings from thecutting edge 2 to the discharge opening 3.

Fig. 1 shows an operating means for rotating the cutter and ejector inopposite directions. The relatively large upper end of the tubularcutter is secured in the lower end of a hollow shaft 5, said shaft beingdriven through the medium of a gear wheel 6 at its upper end. Theoperating means also includes a gear wheel '7, at the top of Fig. 1,meshing with a gear wheel 8 on a hollow shaft 9, and a gear wheel 10 atthe lower end of said shaft 9 meshing with an intermediate gear 11through which motion is transmitted to the gear 6. The hollow shafts 5and 9 are thus rotated in opposite directions. The cutter 1 is securedtothe shaft 5, while the extractor 3 extends through said shaft 5 and issecured to the shaft 9.

12 designates a pile of sheet material arranged on a table 13 below thecutter 1. This table may be lifted by any suitable mechanism While thecutter and extractor are rotating in opposite directions. .The cuttingedge 2 will then form a circular hole in each sheet of the material l2,and the cuttings, or waste material, will be picked up by the sharplower end of the spiral extractor and transmitted to the dischargeopening 3.

The cutting operation is performed by firmly forcing the sheet materialonto the rotating cutting edge 2, thereby forming perforations havingcircular raw edges, and in some cases numerous small fibers extend fromthese raw edges.

In other words, when paper is cut in this manner, the holes may appear`perfectly smooth and round, but there is more or less tearing of thebers and sometimes a slight horizontal displacement of the work duringthe cutting operation. These conditions often result in a high degree offriction between the raw edges of the work and the outer face of theordinary tubular cutter.

However, the tubular cutter herein shown has a tapered outer face whichgradually decreases in diameter from the cutting edge 2, as suggested inFig. 3, so as to provide a space between the raw edges and said taperedouter face. This condition eliminates the highly objectionable frictionwhich occurs at the outer face of @n ordinary straight cutter.

of the cuttings.

The foregoing is quite important, as the cutter is rotated at a highspeed, for example, 1350 revolutions per minute. and if the work firmlyengages the outer face of the cutter, the resultant friction will tendto overheat the cutter. Further more, such friction would tend totransmit a rotary motion from the cutter to the work, thereby mutilatingthe raw edges of the perforations in the sheet material, and at the endof the cutting operation a considerable force, and more or lessmutilation. would be necessary to remove the work from the outer face ofthe cutter.

It will now be understood that the tapered outer face of the cuttereliminates a number of the troubles and uncertainties involved in theold machines of this kind.

Another objection to the ordinary old machines lies in the fact that thespiral extractor does not always perform its function. For example, moreor less adhesive material may cling to the extractor and merely rotatetherewith, instead of rising in the spiral. On the other hand, oilymaterial having no adhesive properties, may slide in a circular courseon the smooth inner face of a tubular cutter, instead of rising in thespiral.

The inner face of the tubular cutter herein shown may be grooved, asshown at 14, to provide for the transmission of a rotary motion from thetube to the cuttings in the spiral extractor. The grooves may be of anysuitable shape, but to illustrate this feature I have shown longitudinalgrooves 14 extending in straight lines from the cutting edge to thedischarge opening 3, each of said grooves having an abrupt radialshoulder 15 (Fig. 4) and a tangential face extending from said shoulderto the circular inner face of the tube.

Figures 3 and 4 show how the cuttings 16 enter into the grooves. Thetangential face permits the edge of the paper cutting 16 to freely enterand remain in the groove, so as to be rmly engaged by the abrupt radialabutment 15. Consequently, when the tube l and extractor 4 rotate in theopposite directions indicated by arrows in Fig. 4, the paper cutting 16is positively rotated with the tube 1, and for this reason alone it mustrise in the spiral. However, the rotary motion of the spiral adds anequal lifting force to the cuttingsl.

Both of these rotary motions tend to force the waste paper cutting 16onto the abrupt shoulder 15, so the cutting cannot rotate idly with thespiral and it cannot slide around the inner face of the tube 1.Therefore, if we assume that the pitch of the spiral is one-half of aninch, the cutting should rise one-inch in response to each revolution ofthe tube and spiral, and in actual practice, these elements ordinarilyhave a speed of about 1350 revolutions per minute.

This involves a very rapid and positive removal They cannot accumulateor become packed in the tubular cutter, so there is no danger ofobjectionable friction or breakage within the tube.

By positively eliminating the objectionable conditions at both the innerface and the outer face of the tube, I have completely overcome theuncertainties herein pointed out, and produced a cutter adapted to beregularly operated at the desired high speed without mutilating thework.

I claim:

A cutter comprising a rotary tube having a circular cutting edge at oneend and a discharge opening between its ends, a spiral extractorrotatably mounted in said tube to transmit the cuttings from saidcutting edge to said discharge opening,

gradually decrease in diameter from said cutting edge and therebyprovide a tapering annular space between the outer face of the tube andraw edges of the material cut by said edge.

BENJAMIN F. BERRY.

